many of us also buy en rated dive gear and then modify/improve it. Afterwards it works much better, but if closely examined has lost it's en rating due to the modifications.
as an example, this is what I've done so far to my SF2 rebreather:
ScubaPro MK17 (not EVO) 1st stages instead of Apeks DS4
Golem Gear DSV
IqSub MAVs
Cooper Hoses
Higher ohmage isolation resistors in the head
Shore 90 O-Ring on the top of the Scrubber
Filed angle brackets on the scrubber in order to make it easier to drop in
JJ Scrim Kit Filters inside the Scrubber (
Really important, I almost killed myself after inhaling around 100ml of sorb dust loaded liquid. see
http://www.rebreatherworld.com/showt...ing-inhalation)
Long Backplate
57mm Standoff under the bottom tube
Replaced all Flex hoses with MTM rubber hoses
1 Kg P-Weight
Shortened the counterlung movement distance by 5cm
and the newest mod to make it easier to get the head off the upper tube:
I filed a wide screwdriver slot into the top of the upper tube front and back (but nowhere near as deep as where the O-Ring sits) just wide enough for my biggest flatbladed screwdriver. Now I stick the screwdriver in the front slot, twist, go around to the back slot, twist, and the head is now off.
What I've now got works much better than the original RB but can no longer be considered to be either EN or CE certified.
Michael